WASHINGTON, Aug. 28 (Xinhua) -- People who are optimistic are more likely to live longer, according to a new study.

"Optimism is specifically related to 11 to 15 percent longer life span, on average, and to greater odds of achieving 'exceptional longevity,' that is, living to the age of 85 or beyond," the report said.

U.S. researchers studied survey data collected from 69,744 women and 1,429 men, who were asked to assess their level of optimism and overall health as well as habits.

The females were followed for 10 years and men for 30 years in the survey. Most of the participants are white with high socioeconomic status.

The relationship between optimism level and longevity was adjusted based on factors including demographics and health behaviours, according to the researchers.

"Other research suggests that more optimistic people may be able to regulate emotions and behavior as well as bounce back from stressors and difficulties more effectively," said Laura Kubzansky, a co-author of the study report.

Further researches are needed to see how optimism could attribute to longevity, as well as if current findings hold universally.

The study was published Monday in the journal Proceedings of the National Academy of Sciences.